Key to species of the genus Darnilia van Achterberg

1. Length of eye 3.5 × as long as temple in dorsal view; occipital carina complete, but medio-dorsally weakly developed; basal half of third metasomal tergite distinctly striate medially; hind wing vein 2-SC+R quadrate (Fig. 319 in Chen & He, 1997); Eastern-central China (Jiangsu)............................................ Darnilia chinensis Chen & He, 1997

- Length of eye 5.5–11.0 × as long as temple in dorsal view (Figs 1, 13, 24); occipital carina interrupted medio-dorsally (Figs 13, 24); basal half of third metasomal tergite only finely granulate-coriaceous; hind wing vein 2-SC+R slightly longer than wide (Fig. 22)............................................................................................ 2

2. Eye large, length of eye approx. 11.0 × as long as temple in dorsal view (Fig. 42 in van Achterberg, 1989); first metasomal tergite with median carina in basal 0.3 of tergite (Fig. 44 in van Achterberg, 1989); vein cu-a of fore wing vertical; Indonesia (Sumatra)........................................................... Darnilia flagellaris van Achterberg, 1989

- Eye medium-sized, length of eye 4.5–6.0 × as long as temple in dorsal view (Figs 13, 24); median carina of first metasomal tergite absent (Fig. 10) or complete (Fig. 28) or at least in 0.4–0.5 basal of tergite (Fig. 21); vein cu-a of fore wing oblique or vertical.............................................................................................. 3

3. OOL shorter than diameter of posterior ocellus (Fig. 24); first metasomal tergite coarsely longitudinally striate (Fig. 28); propodeum with triangular ivory patch (Fig. 31); [first tergite subequal or slightly longer its apical width (1.1–1.2 x), its median carina complete (Fig. 28) or nearly so; occipital carina narrowly interrupted medio-dorsally (Fig. 24); vertex shiny and finely aciculate]; Vietnam............................................ Darnilia vietnamica Long & van Achterberg, sp. n.

- OOL equal to diameter of posterior ocellus (Figs 1, 13); first metasomal tergite without striae or with comparatively fine longitudinal striae (Figs 10, 21); propodeum variable, often largely brown or dark brown (Figs 8, 20)....................... 4

4. Second metasomal tergite distinctly finely granulate (Fig. 11); vein 1-M of hind wing 1.1–1.6 × vein M+CU; striae of vertex obsolescent or mixed with other sculpture, rather dull; first metasomal tergite 1.0–1.1 × its apical width, without median carina; first–third tergites without a trace of striae (Figs 10, 11); Vietnam... Darnilia granulata Long & van Achterberg, sp. n.

- Second metasomal tergite finely granulate-coriaceous (Fig. 21); vein 1-M of hind wing 1.7–2.2 × vein M+CU; striae of vertex distinct, shiny; first metasomal tergite 1.2–1.4 × its apical width, rarely subequal, its median carina usually present as a short carina, but sometimes absent or complete; surface of first-third tergites finely striate or only granulate-coriaceous (Fig. 21); Vietnam..................................................... Darnilia intermedia Long & van Achterberg, sp. n.